Motion Picture Experts Group (MPEG)-H three-dimensional (3D) audio can process various types of signals, and functions as a solution for next-generation audio signal processing since control of an input and output form is easy. In addition, due to a tendency of miniaturization of devices and trends of the present times, a proportion of audio being reproduced by mobile devices in a stereo reproduction environment is increasing.
When an immersive audio signal implemented by multiple channels such as 22.2 channels is transmitted to a stereo reproduction system, all input channels must be decoded, and the immersive audio signal must be down-mixed and converted into a stereo format.
As the number of input channels increases, and as the number of output channels decreases, complexity of a decoder required for covariance analysis and phase alignment in a decoding and conversion process increases. This increase in complexity significantly influences not only an operation speed of a mobile device but also battery consumption.